Power transmission



May 25, 19484 E. .1. HART 2,442,169

POWER TRANSMISSION Filed Feb. 17, 1944 2 Sheets-Sheet 2' 5 [WMM l wm 1| IIIWW/ S Y INVENTOR.

ELMER J. HART Patented May 25, 1948 UNITED STATES PATENT CFFICE 3 Claims.

This invention relates to power transmissions and is particularly adapted for driving airplane propellers.

The primary object of the invention is to utilize air as a liquid power transmission medium to transfer rotation from one rotating element to another.

A further object of this invention is to utilize this air medium to assist in driving an airplane motor forward as the same is exhausted from the transmission unit.

By the using of high velocity air between a driving rotor and a driven rotor, a speed reduction can be obtained with the minimum amount of wear to the transmission.

These and other incidental objects will be apparent in the drawings, specification and claims.

Referring to the drawings:

Figure 1 is a front elevati-on of an airplane propeller including my new and improved power transmission, the propeller and :transmission assembly being mounted to a conventional motor within a supporting housing.

Figure 2 is a fragmentary side sectional view of Figure 1, parts broken away for convenience of illustration.

Figure 3 is a modified form of' embodiment of Vmy new and improved power transmission.

Figure 4 is a front view of my invention, illustrating a standard propeller in connection therewith.

Figure 5 is a fragmentary view of a propeller and motor fuselage, parts broken away for convenience of illustration.

Figure 6 shows my invention adapted to a helicopter.

With particular reference to Figures 1, 2 and 3, my transmission consists of a rotor 8, iixedly mounted to the motor shaft 9 by a suitable key 8A. This rotor turns with the motor shaft at all times. The motor 2| is mounted within the casing 20, which may be the fuselage of an airplane or it may be a motor housing mounted within the wings of an airplane. In any event, the casing or housing 20 is held rigidly to the plane and does not revolve relative to the plane.

The rotor 8 consists of radially mounted blades I being spaced apart by the parallel annular rings 28 and 29. The blades IU and the rings 28 and 29 are mounted to the spokes I2, having a hub 3D keyed to the drive shaft 9. The assembly ofthe blades Ill,` 28 and 29 including the hub and spokes, is similar in construction to a squirrel cage blower, and in effect the assembly acts like a drum squirrel cage blower unit as commonly used in blowers of this type.`

My invention consists of surrounding this rotor with a series of vanes I8, curved as illustrated Iin Figure 1. These vanes are fixedly mounted between the parallel side rings or end pieces I5. This unit resembles a .turbine blade assembly and will hereinafter be described as a turbine drum I1, and is rotatably mounted to the drive shaft 9 in the following manner.

The propeller I3 has its hub I3A mounted to the shaft 9 through a suitable bearing I4 and rotates freely .on the shaft. The propeller supports the turbine drum l 5 by the holding lugs I9 being secured to the hub 26 of the turbine drum. The propeller holds the drum in spaced relationship to the rotor 8 so that the rotor 8 will revolve freely therein. An annular bell shaped ring 22 completely surrounds and is spaced apart from the housing 20. The forward end of the ring 22 is curved, as illustrated at 23, and is open at the rear 24 completely surrounding the housing 20 of the motor 2|. The ring 22 is mounted to the motor housing 20 by spaced braces 25 completely around the housing.

I-will now describe the operation of my power transmission. Free air enters through the central opening in the hub 26 of the turbine drum and into the rotor 8, which is being driven by the motor through the shaft 9 in the direction of the arrow. Air may also enter through the rear central opening 2l of the turbine drum I1 and a registered opening of the rotor 8 adjacent the motor 2|. This air is forced out through the blades of the rotor 8 by centrifugal force, similar, to a squirrel cage blower. The air enters between the vanes I8 of the turbine drum I1 at 3|., and follows the curvature lof the vanes as illustrated by the arrows, rotating the turbine drum in the direction ofthe rotor by the velocity of the air from the rotor acting upon the curved surfaces of the turbine drum vanes I8, imparting a rotation to the propeller I 3 through the concentrically attached turbine drum. Further propelling force is exerted in the direction of flight by the action of the exhaust air striking the curved surface 23 of the annular ring or drum 22, forcing this exhaust air in the direction of the arrows through the opening 24 against atmospheric pressure. The reaction of this high velocity air being delivered by the rotor against the surface '23 and out the opening 24 against the atmospheric pressure creates a force against the surface 23 of the annular drum 22, forcing the unit forward and assisting the propeller I3 in driving the plane forward.

Y longitudinal aids.

`completely surrounding the housing of the motor unit.

As described before, the reaction oflthezhigh velocity air through the opening 2li tends to back up a pressure against the surface 23L byl the" back Y pressure developed by theatmospheric -pressure against the high velocity Yescaping air.

In the modied form'of Figures 4 and 5,.the invention is applied to the motor housing I of airplane motors, having theusual propellers 2driven by the motor shaft 3 of the motor. Y i

The invention consists of mounting `specially Vformed vanes 4 radially around and-'tothe housing i. The housing l lforms part of the `airplane fuselage or'vwring and supports andhcusesthe motor. The housing I does notrevolve with the propeller but isV fixed relative to theairplane.- The outerends :of the vanes are braced by -therring band 5, secured to the vanes.at-6;this.band also controls air currentsfto be described later.

Y When lthe propeller of anaairplanelis drivenby the motor, :a rbackward torque iseierted against the `fuselageof the airplanegwhichvhas been an objectionable feature in ,propeller `action. y My invention tends to eliminate .this=effect, at the Sametime using the energy of the slip stream of the propeller for useful forward propelling power.

VVThe vanesgiare shaped-.as illustrated so aseto catohthe slip stream fromY the propeller, as indicated by thearrows in the cup-like-.portion 1, eilierting a rotating.v force against the'vanes 4 in the direction of rotation of Y the. propeller, vovercoming the backward propeller torque exerted against: the motor as described above. 'Ihfis.- force does not literally rotate the housing and vanesgll, `but is an vunseen' existing force overcoming Atorque .de-

Yvelopedvibylthe propeller. Y Y Y In the operation oflpresent-daylairplane pro- V `pellers, the propeller exerts Yabaclcward torque against-the'motordueto the-power required to rotate the. propeller. In present-day propelleriaction, aslipstrea-m of air of high velocity isforced rrearwardly and spirally from'the-propeller. My invention; utilizes this spiralslip stream by causingitfto enterfthe pockets 'l .oir the vanesJLexertingla force` against these'vaneacvercoming propeller torque relative Vtotheplane, eliminating thtendencylfor the planeV to revolve -about its -Heretofore v.this Vtorque. effect was f overcome by `the planecontrols, as for in'- stance` in the manipulationof the ailerons v.and tail surfaces, rwhichV tended -to-.throwthaplane out .ofi-balance. .By using theuoevolving'slip stream from=the propellerpagainst Vthesuriaces of the i vanes, the desiredeiect may-befobtained without theuse of theplane controls.

The eiciency of the .propeller '2 is increasedby its slip stream'enteringthrough'thetvanesll in thedirection ofthe. arrows. Theslipstream tends to followthefrotation of thepropeller, andas'it entersjbetween the'vanesrat.;A,'it strikes the .inner surface at p6B, developing ;awforw'ard force againsttheivanes: asiit tries-to escape rearwardly against the ,atmospheric 'pressure `-atthe 'srearA of the vanes. As the slip stream passes throughY the varies, as just described,` it straightens out parallel to the line of flight driving against the atmospheric pressure and reacting against the rearV of the vanes at 1, creating considerable additional propelling force.

Referring to Figure 6, IV have illustrated my invention applied to a helicopter, which it will be admirably adapted to, and which'will eliminate torque: which has heretofore' been objectionable,

requiring' various kinds of stabilizers.

I do not wish to be limited to the use of my ytransmission in airplanes, as it may be adapted to l'otherfuses still coming within the scope of my claims. In many instances, the reaction of the air against-atmospheric pressure would not be utilized, lasforinstance when the device is applied to vehicle transmission or transmissions used lin factories and the like.

What I claim is: y

il# A power transmission :or .the. class described Afor air-plane fpropellers, the same including in combination with an airplane itself otherwisecon-V ventional .and carrying a motor'mounted station'- -ari-ly fthereen, a -forward propeller :shaft ydriven rotatably byfthe: motor, a propeller journalledzcoaxially and loosely but held longitudinally-immov- Y able on 2 said shaitf-a squirrel cage Ytype `rotary blower `element,Iiixedly mounted co-axially onV said 4shaf t rearwardly of the Ypropeller yand delivering air under pressure peripherally vfrom. normal outsideairudraf-.vn centrally into said blower, element upon powerfrotationof` -said element, anannular Vturbine typey rotor Ydrum, surrounding said blower element and connectedloperatively andconcentrcallytc the propellensaid turbine rotor drum having anannularseries ofspaced vanesfdisposed in the region of its periphery :and betweenvwhich the air undenpressure from-theablower element is discharged, 4said A.vanesvbeing Vformed `so as `to cause-.thevair discharged ffrom-Lt'nev blowerwelement .to-.rotate the turbinei rotor. drum and. thereby/.ro-Y

tate the propeller in the. .same direction ofgroT tationas the Kpropeller shaftgandstationary-an Y nular elementhaving itsdischargeopeningrearward and opposite to the direction f flight of the airplane with a concavo-convex annular front wall, thejfree circular lower edge of which is annularly ycontiguous to'Ythe"preripl1eralv front edge Vor the turbine rotordrumytheconcave face of said front wall being interior of the element and producing an annular transversely curved corner 'fillet formation of 'substantial radius and merging roundingly with theannular wall ortheelement.

'73. :A kpower transmission, provision and arrangementas setiorthin claim 1,.wherein the r0- taryfblowerelement is providedwithfan annular series of peripherallyzadjacent radial spacedapart blades ;:and the turbine irotor ldrum is provided withraneannular; Vseriesi oft generally 4fradially'sdis- 5 posed but relatively inclined and more restrictedly spaced apart curved vanes rotatively surrounding the annular series of blower element blades and in close working relation thereto, the inclination and curvature of said turbine rotor drum vanes being such that the air under pressure passing therebetween and thereagainst effects rotation of the drum in the same direction as that of rotation of the blower element, and the stationary annular gatherer and delector means for the air under pressure as discharged from the turbine rotor drum comprises a cupped annular element having its discharge opening rearward and opposite to the direction of flight of the airplane with a concavoconvex annular front Wall, the free circular lower edge of which is annularly contiguous to the peripheral front edge of the turbine rotor drum and the concave face of said front wall being interior of the element and producing an annular transversely curved corner llet formation of substantial radius merging roundingly with the annular wall of said deector element.

ELMER J. HART.

REFERENCES CITED The following references are of record in the 111e of this patent:

Number 20 Number 6 UNITED STATES PATENTS Name Date Radcliffe Feb. 21, 1911 Lake Feb. 13, 1912 Dobbins Apr. 13, 1920 Ramsay Oct. 10, 1922 Cupp May 29, 1923 Wagner Nov. 20, 1928 Goddard June 9, 1931 Murphy Nov. 22, 1932 Chilton Feb. 7, 1933 Vaughn Sept. 5, 1933 Wright Dec. 12, 1933 Gwinn July 2, 1935 McMahane Feb. 8, 1938 Morris Nov. 18, 1941 Adler Nov. 18, 1941 FOREIGN PATENTS Country Date Netherlands Apr. 15, 1935 Germany Mar. 8, 1918 Great Britain May '7, 1941 Great Britain Nov. 4, 1942 

